Plycem Panels. Plycem has the strength and stability that maintains attractiveness for long-term durability and value. The Plycem is fire-resistant and also resists damage that can be caused by mold or moisture. It is recommended for walls, floors and roofs and itÕs easy to cut and install. Available in 4Õ x 8Õ and 4Õ x 10Õ sizes, with thickness: 1/4Ó, 3/8Ó, 1/2Ó, 5/8Ó, 3/4Ó and 1Ó.